GREEN BAY, Wis. (AP) – Prescription opioids claimed the lives of about 300 people each year from 2006 to 2012.

That’s according to data from the state Department of Health Services, obtained by Gannett Wisconsin Media.

Opioids are narcotic drugs like OxyContin, Percocet and Vicodin typically used for pain relief and contain a synthetic form of opium, the core ingredient in heroin. They are the primary gateway to heroin use.

Between 297 and 329 people died from prescription opioids each year from 2006 to 2012, as heroin deaths rose five-fold. All but six counties reported at least one opioid death.

Louis Oppor, a substance abuse expert with the state health department, says it’s not clear how many deaths were related to non-medical drug abuse and how many to accidental overdoses.